Jerry Renault, a freshman at Trinity High School, has a confrontation with the school gang, The Vigils. The Vigils, headed by Archie Costello, specialize in making assignments that other students have to complete. These assignments vary, depending on the person, and intend to inflict as much psychological injury as possible. Early in the book, Jerry's friend known as The Goober gets an assignment from The Vigils. He sneaks into one of the classrooms at night and unscrews desks, chairs and hinges, leaving the screws in by just a thread. The next day when students come to class, everything collapses and falls apart. The Goober suffers some serious emotional repercussions from carrying out the assignment and is never quite the same afterward.
Jerry gets called to carry out an assignment and he is to refuse selling chocolates at the annual school chocolate sale. Archie gives him this assignment despite the fact that Archie told Brother Leon, the teacher in charge of the sale, that he and The Vigils would support the sale and make sure it is a success.
At first, Brother Leon and the other students are shocked by Jerry's refusal. Eventually, it becomes common knowledge that Jerry's refusal is prompted by a Vigils assignment. Brother Leon, at first outraged, looks forward to the assignment ending, since after ten days, Jerry is supposed to accept the chocolates and begin selling them.After the tenth day, Jerry fully intends to accept the chocolates. When Leon calls his name during the chocolate roll call, however, Jerry blurts out "no." When The Goober asks Jerry why he refused, Jerry does not have an answer. He is rebelling against The Vigils and Brother Leon. Inspired by the poster in his locker that reads: "Do I dare disturb the universe?" and Jerry decides that that is precisely what he will do.
The Vigils consider Jerry's refusal to sell a defiance of their assignment. They call Jerry into a meeting and ask him to sell the chocolates the next day. The next day, Jerry still refuses. Soon, he is somewhat of a hero in school as other students consider refusing to sell their chocolates too. The sales figures dip, and Brother Leon gets upset. The school treasurer overhears him telling another teacher that he spent unauthorized money to buy the chocolates and that to break even he has to sell them all.
Archie and Brother Leon have a meeting in which Brother Leon accuses him of sabotaging the sale by creating Jerry's assignment. Archie decides that the best thing to do is to make the sale popular and make Jerry an outcast. Soon, the chocolates are selling like hotcakes, and boys who really have no sold boxes are getting tallies as if they have. It is obvious that The Vigils are selling all the chocolates. Meanwhile, Jerry still refuses and The Vigils are making his life hell. They are calling him at all hours of the day and night, and then hanging up. They are swiping his homework assignments, and trashing his locker. He even gets beat up by a gang of kids after football practice.
Finally, all of the chocolates except Jerry's have been sold. Archie wants to get back at Jerry and get something out of all the work he put into the chocolate sale. He schedules a student-only assembly to raffle off the tickets. The raffle is a special one, however, which pits Jerry against school thug Emile Janza. The students who buy raffle tickets get to write on them a boxing move, directing Jerry to hit Janza or vice versa, and where. During the fight, Jerry and Janza are hitting each other as directed. Janza is much stronger, and his punches have much more staying power even though Jerry lands a good hit of his own. Then, a member of The Vigils draws a raffle ticket that tells Janza to hit Jerry in the groin. Jerry blocks the punch, and the warfare begins. Janza decides not to abide by any rules, and punches Jerry over and over. Finally, after Jerry collapses, the lights in the stadium go off. Brother Jacques is there, stopping the ceremony. Brother Leon is also there, and has been from the beginning, watching. He makes sure that Archie is not punished.
Jerry has a broken jaw and possibly some internal injuries. As he is waiting for the ambulance he tells his only friend, The Goober, not to disturb the universe—that it is not worth it. The book ends as Archie displays no remorse for the past, and Jerry no hope for the future.